The recent increase in reliance on optical communication systems and optical networking has led to major developments in the field of optical devices and their control systems. Recently there has been a move towards the development of network control systems for optical devices. Essentially this means that a host optical system controller is networked with a multitude of optical subsystem controllers (referred to as subcontrollers). Each subcontroller directly controls at least one optical device. Clearly this development requires that methods of communication between the host controller and the subcontroller be developed. Unfortunately, as it stands there is no generic communications protocol between a host optical system controller and its subcontroller. Because of this, manufacturers have had to develop their own in-house protocols leading to a lack of compatibility between the products of different manufacturers. Not only that, but these in-house protocols are not upwardly nor downwardly compatible in that a new system's protocol will only work with that system's devices. It cannot work with legacy devices nor with devices that are subsequently developed. Unfortunately, this leads to higher development costs for systems in terms of both time and resources as each new system will have to be re-engineered to work with legacy devices.
It should also be noted that the current developments in the field of optical devices have given rise to electronically reconfigurable devices. Lasers, tunable filters, switches, and other optical devices can now be reconfigured on demand to more efficiently transfer or route optical channels. Real-time control of these devices has led to better control and more efficient use of resources. As an example, a diode laser operating at 980 nm can now be controlled in real time to provide the proper amount of amplification needed by channels passing through a system. A tunable add/drop filter can be requested, in real-time, to add or drop a particular channel or service to arrive at a specific and desired result. This real-time capability of current optical devices is well suited to the use of subcontroller which provide an interfere between the electrical/computer side of a control system and the electrical/optical device side of physical optical devices.
Since subcontrollers receive control data at one end and translate this into specific optical settings, a common data interface and protocol between these controllers would be particularly advantageous. Such a development would simplify the control scheme and allow interoperability between devices from different vendors. Furthermore, using a networking framework for such a control scheme would allow the migration of formerly network based technologies into the optical device control arena. And last, but not least, the interchangeability between optical devices attached to a subcontroller would speed device and device interface standardization in the optical device industry.
From the above, it is clear that there is a need for a communications protocol or a method of communicating between host and subcontrollers that is not only robust but can service the needs of not only legacy but also of future devices.